Process and apparatus for reducing cotton-stalks to pulp suitable for the manufacture of paper.



I. M. IRWIN.

PROCESS AND APPARATUS FOR REDUCING COTTON STALKS T0 PULP SUITABLE FORTHE MANUFACTURE 0F PAPER.

APPLlcATloN 111.511 sEPT.14.1916.

Patented Dec. 11, 1917.

l/VI/ENTUR A TTOR/I/E r IvfI 1 narran santas ramena ernten.

JESSE M. IRWIN, OF DALLAS, TEXAS.

PROCESS AND APPARATUS FOB REDUCING COTTON-STALKS T0 PULP SUITABLE FORTHE MANUFACTURE OF PAPER.

pasaros.

Specification of Letters Patent.

Patented nee. ai, wir.

Application led September 14, 1916. y Serial No. 120,020.

State of Texas, have invented certain new` and useful Improvements inProcesses and Apparatus for Reducing Cotton-Stalks to Pulp Suitable forthe Manufacture of Paper, of which the following is a specication.

This invention relates to new, useful and effective processes andmethods for reducing, drawing out and extracting the Vfibers fromvegetable matter and tissues, and particularly it is a process forreducing cotton stalks to pulp suitable for the manufacture of paper,and for such other and further uses to which vegetable pulp may be put.

The object of this invention is to= provide a process and method whichwill combine in compara-tively few or a single working operation thedifferent stages which have been necessary vto properlyreduce vegetablematter to pulp.

Upon information gained through extensive experimentation it is foundthat the useful vegetable fiber of the cotton stalk can best be drawnout by a combination of mechanical and chemical operations.l Thisinvention contemplates such combined use of the two means in a singleoperation to effectively reduce cotton stalks to a fiber or pulp.

One form of such mechanical means is illustrated herewith and forms anillustrative part of these Letters Patent, said illustrations beinggiven of the machine to aid in a comprehensible understanding of themethods of pulp reduction as herein set out in the appended claims.

Previous to the development of the description of the methods andprocesses hereinafter described, a description of the pulp reducer ordigester will be given.'

In the drawing Figure 1 illustrates a longitudinal vertical sectionalview of the mechanical digester used in connection with the process.

Fig. 2 is a cross sectionalview taken upon the line 2 2 of Fig. l.

Fig. 3 is a diagrammatical illustration of correlated Crushers ordigesters provided upon the reducing apparatus.

Fig. 4 is a diagrammatical view showing the diameter and length ofv samebeing so designed as to obtain the most efficient working results.y 'Theinterior of the digester boiler or cylinder will preferably be bored orground which will give the interior a form o f a perfect cylinderadaptable to receive close fitting moving mechanical digester elements.vThe outer shell or boiler2 is provided on the digester boiler and hasconnection with the steam pipe 3 provided with a' control valve 4. Thesteam pipe connects with any suitable source of steam supply sufficientto raise the temperature of the annular space formed by the outer shellto a high degree or boiling point. Pipe connections 5 are provided andopen into the boiler at each end thereof, said pipes are joined and havea common connection with pipe lines 6, 7, and 8, which pipe lines areeach provided with a hand valve 9, `adaptable to either allow theliquid, contained in the supply with which the said pipe lines connect,to pass into the boiler or withhold it therefrom. A substantially largescrew plug 10 and 12 are provided in one head of the boiler, the plug 10being of sufficient size to admit of the introduction of cotton stalksor vegetable matter to be reduced into the boiler, the screw plug 12being provided to draw oli the pulpa' A 'substantially large drain pipe13 enters the lower portion of the boiler and is adapted to be used indrawing off the several and various liquids which will be used inconnection with the reduction process carried on within the boiler,said. pipe being provided with a cut o valve 14.

A substantially large and strong screwand fixed in an immovable relationto its points of support. A digester' wheel 16 with an integral extendedhub l? is screwythreaded shaft l5 is arranged in the boiler threadedupon the shaft and adapted to be revolved thereupon by means hereinafterdescribed. A companion digester wheel 16 is provided and has an axis ofrotation common to the first named digester wheel and adapted to be runin substantially close contact with the first named wheel. rl`he twodigester wheels as illustrated are similar in design and construction,each provided with a central hub as illustrated from which radiateintegrally formed webs or blades 18, which webs integrally connect withthe rim 19 of the wheel. The function of the digester wheels and bladesthereof is to attack and reduce cotton stalks contained in the reductionboiler to pulp by catching the stalks and limbs thereofl between thewebs or blades and subjectingthem to a crushing, rolling and drawing outoperation. It will here be understood that the digester wheels areadapted to revolve in opposite directions which permits the webs orblades of the dgester wheels to pass one by the other in closerelationship. rlhe forward advancing edges of the webs are flared out asindicated in the diagrammatical views Figs. 3 and 4. The following edgesof the webs gradually turn inwardly in a curvilinear form until the edgeof the rim of the wheel is approximately reached where the remainingportion of the said web is formed in a parallel relation with the planeof the rim of the wheel. lThis brings the following rear portions of thewebs into a close relationship one with the other, and into such a closepassing position as to admit only very small vegetable fibers to passthereinbetween. Said following rear portions of the webs may be termedthe working faces or portions of the webs, which workimgfaces of thewebsI as later seen will attack and by attrition roll7 crush, reduce anddraw out the fiber from the cotton stalk.

substantially large and heavy shaft 20 has one extremity fixed in thehead of the boiler and in contact with the extremity of thescrew-threaded shaft, a pin Q1 being employed to'fix them one to theother in an immovable relation. A tubular shaft is provided andjournaled upon the shaft 2l), said tubular shaft passing through thehead of the boiler and having its inner extremity lying' in contact withthe extended heb of the wheel 1G. screw-threaded connectingn sleeve isprovided and adapted to join in a fixed relation the tubular shaft with'the wheel 1G in such a way that said wheel nav be driven in revolutionby the tubular s ia ft 2Q. A. tubular shaft Q4 is confined on firstnamed shaft and journaled on itsl inner ex tremitv upon the connectingsleeve jflK and journaled upon its outer e\tremit\r on a bearing 24. themembers Q25 and iii serving to support the shaft 2li in jonrnaledrelation upon the shaft 9.2. The second named wheel is fixed upon theshaft and adapted to be driven in revolution by said shaft.

A motor is movably arranged upon the shaft 20, the base of said motorbeing so arranged as to allow the motor to slowly movev along in anupright position l the length of the shaft. Said shaft is provided witha groove or channel. extending the entire length thereof. The motor basewhich is confined upon the shaft is provided with a rib which lieswithin and engages the walls of the channel, holding said motor in avertical and upright position. Gears 2G and 27 are fixed upon the motorshaft. A reverse gear 28 is carried by a stud xed to the motor base. Agear 29 is fixed to the extremity of the tubular shaft and engages thereverse gear 28. A gear 30 is fixed to the shaft 24; and engages thegear 26. rlhe means of transmission, as 'Just described, with the gearQ8 interposed between the motor and the shaft allows the shafts to.bedriven in an opposite direction which carries the digester wheels in anopposite direction one from the other. it thrustbearing 31 is'confinedupon the shaft 22 and interposes between the gear 29 and extrem ity ofthe shaft 24s.

rlhe motor during the operation will drive the two shafts in an oppositedirection one from the other, the shaft 22 driving the wheel 16 andmoving it along the screw-threaded shaft 16 'causing said wheel totravel along the length of the boiler as said wheel revolves. 'lhroughthe agency of the thrust-bearing 31 interposed between the gear Q9 andtubular shaft 24 the corre lated second named digester wheel will beconfined to the same longitudinal travel and speed as wheel 16 isundergoing. The assembly and arrangement of the mechanical digester asdescribed provides a pair of' correlated oppositely revolvinglongitudinally traveling digester wheels adapted to revolve with theirperipheries in close contact. with the inner walls of the cylindricalboiler.

Figs. 3 and d are diagrams illustrative of different and varying operatipositions `to the webs or blades of tliedigesier wheels. .lf 3 shows theoppositelyY traveling webs or blades as indicated by the arrows and thefollowing rear working facs of said blades approaching each other. el:illustrates the correlated working webs or blades in their oppositedirection of travel as indie.L ted by the arrows and with the followingor trailing working faces passing each other in very close relation onewith the other.

lhe digrster wheels are adapted to be driven at a substantially slowspeed ranging fr-ni one hundred to three hundred revolutions per minutewhich will cause the entire assemblage of the bearing transn'iis- Fill SSi

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sion arrangement herein disclosed to travel along the shafts. Owing tothe slight pitch of the thread upon the shaft the digester wheels willrequire considerable time in traveling from one extremity of the boilerto the other. At the time the digester wheels have reached the end ofthe boiler it will be necessary for an attendant operator to reverse thecurrent through the motor vand start the correlated digester wheels insolving agents into the boiler with the mass.

The cotton stalks will be harvested and introduced into the digesterboiler through the plug 10. The boiler will be filled with said stalksand the machine set in operation, at the same time the water supply pipeline 6 will be opened allowing water to liow through the pipes 5 intoeach end of the boiler. The tremendous agitation and attrition set up onthe interior of the boiler .by the operation of the oppositely revolvingdigester wheels will thoroughly wash and cleanse the stalks of any dirtor foreign matter which may have been included as the stalks were placedinto the reduction boiler. After a sufficient washing process is carriedon the water pipe line is closed and all the water allowed to drain fromthe boiler through the conduit 13.

With the digester wheels in continuous operation the pipe line 7 isopened which ad mits to the boiler the flow of cooking liquor orreducing liquid. The pipe line 7 connects with any suitable reservoirwhich holds in storage and in reserve a quantity of previously preparedcooking liquor or stalk reducing liquid, which liquid is a chemicalsolution consisting of any strong alkaline, or caustic preparation.Preferably a preparation of potassium hydroXid or caustic potash in theper cent. of about one tenth, thoroughly mixed with water7 will be usedin the mechanical digester in connection with the reduction. After thecooking is introduced into the digester boiler and the revolvingdigester wheels have been in continual operation for a considerableperiod of time the stalks will be rolled, mashed and drawn and by thecontinual attrition of the coperating blades of the wheels and by thechemical attacks of the reducing liquid upon the stalks the same willbegin to take on a semi liquid condition until the whole mass containedin the boiler will be reduced to a homogeneous plastic semi liuid pulp.

During this operation as described steam can be used to advantage andfurther assist and hasten the disintegration and reduction of the stalksby admitting steam to the boiler and keeping the cooking liquor to avery high temperature. Steam may also be admitted to the annular steamchamber contained between the boiler and the outer shell, this willraise the temperature .of the boiler to a high degree and keep thecooking liquor and reduction liquor very hot. After the stalks arethoroughly reduced and all the liber of said stalks are drawn and-divided and disintegration is thorough, the steam and cooking liquorpipe lines wlll be closed and the water pipe line again opened at whichtime the large drainage conduit 13 will also be opened. 1

The strainer devices contained in the head of the conduit 13 willprevent the mass of pulp from flowing from the boiler to allow the waterand cooking liquor to pass out freely. With the digester wheels incontinual operation the fresh water supply will be turned into thedigester boiler. The water will be ready to run and mingle with thereduced pulp until the cooking liquor has been thoroughly washedtherefrom which will leave the mass inside the boiler a clean pulp freefrom cooking liquor and free from the caustic and aciduous solutions.

The pipe line 8 having connection with the pipe lines 5 also has directconnection with a reservoir or storage tank not shown. Said storage tankis provided to contain suitable bleaching liquids and preparations whichmay be used to bleach whiten and further prepare the pulp for commercialpaper making. After the washing process i-,s thoroughly completed andthe water drawn from the digester boiler the bleaching liquid pipe line8 will be opened and a certain quantity of bleaching chemicalsintroduced into the boiler, while the digester wheels are in continuedoperation. After the bleaching operation is thoroughly complete and themass is whitened to a desired degree the operation of the digesterapparatus will be discontinued and the pulp drawn from the digesterboiler through the plug 12.

The design of the two correlated 'digester wheels with their cordinatedattrition blades or webs is such that a. space or opening is leftbetween the blades of the wheels when said blades orwebs are registeredone with the other, or when one blade is directly behind the other., Atthis period of the travel of the wheels it would seem that aconsiderable quantity of stalks or pulp would escape or pass unground bythe wheel. But the advancing curvilinear design of the blade and itsoutwardly projecting contour in respect to its advance of travel will infact pass forward and scoop or pick up and throw back any quantity ofstalks or unreduced pulp toward the first Wheel. rlhe blades of thefirst wheel will immediately catch the stalks or pulp and cause same tobe confined in the press formed between said blades and as the movementof the blades continue the pulp will be gathered closer and closer inbetween the diminishino' space formed between the blades and wil berolled and ground and reduced b y friction to fibrous matter. As thepulp is r duced to a very fine texture and dissolved into a semi-liquidand homogeneous state, it will be so line in texture that the wheelswill no longer catch it and confine it therebetween but will-allow thereduced mass to squeeze and run by the blades of :the wheel.

When the digester wheels start in their movement from one end of thecylinder to the other a considerable pressure will be exerted on themass in front of the forwardly advancing digesterwheels. This pressureis set up by the positive drive along the screw-threaded shaft of thesaid digester wheels, which pressure will cause the mass of matter infront ofthe wheels to be pressed into the revolving blades. Therevolving blades will have a tendency to some extent to cause the massin the boiler to revolve, which vmovement on the part of the unreduce'dmass will not effect the passage of the unreduced stalks and pulp intothe wheels since the pressure on the mass generated by the wheels willbe sufficient to project same into the blades.

The tremendous heat set up in the reduci-ng boiler through the agency ofsteam coinbined with the disintegrating and attacking capacity of thereducing liquids combined with the tremendous and vigorous attritemovements of the oppositely revolving wheel will thoroughly andeii'ectively break up, reduce, divide, disintegrate and draw out the.fiber of the cotton stalks leaving the mass of pulp consisting of afiber of considerable tensile strength and length, which iiber whenmanufactured into paper will have a 'high degree of tensile strength andinterior cohesion. Y

rlhe process and methods herein disclosed to be used in connection withthe reduction of cotton stalks to commercial pulp is presented toinclude those variations and changes in degree of operation whichhereinafter may be resorted to in obtaining similar results when suchvariations are construed to come within the meaning of the followingclaims:

l. In a process for the reduction of cotton stalks to pulp, the initialstep of placing the cotton stalks in a container, the hydration of thestalk mass, then subjecting the mass to medion chemical action, and themass alternately compressed first from one end of the container thenfrom the other, during which alternate compressing periods theindividual stalks and fiber bod to pass through andI between movinginterstices of the container setting up such a frictional engagementbetween the stalk or fiber body and the machine element as to cause thetentacles and fiber to be drawn and abstracted from the body of thestalk.

2. ln a pulp reducing machine forthe purpose of reducing plant growth topulp suitable'for the manufacture of paper, the combination With acylindrical boiler containeiga shaft axially arranged in the container,and a plurality of revolving attrition Wheels mounted on the shaftadapted to travel among the mass of plant growth reducing same to pulp.

3. in a pulp'reducing machine, the combinationfwith a boiler container,of a shaft axially arranged in the container, a pair of bladed grindingwheels mounted upon the shaft and adapted to travel along the shaft ofthe mass are caused from end to end simultaneously as said wheels are ina motion oit' revolution.

4. ln a pulp reducing machine, the coinbination of'a cylindricalcontainer, of a' screw threaded shaft fixed in the container, a pair ofb-laded attrition or grinding wheels carried upon the screw threadedshait and adapted to ltravel along the threads f the shaft and among themass of matter to be reduced.

5. in a pulp reducing machine ot the character described, thecombination with a steaming and cooking boiler wherein the mass ofmaterial to be reduced may be steamed, hydrated and cooked in one andthe sainecontainer, of a plurality of bladed attrition Wheels arrangedin a contiguous relation one with another adapted to pass back andthrough the mass to be reduced in such a, manner that :Erictionalengagement is set up between the several attrition wheels as the mass isforced through the contiguous blades of the said wheels.

6. in a pulp reducing machine, the coinbination with a container usedfor the purpose of hydrating, steaming and cooking the mass, of a shaftaxially arranged in the container, of two attrition wheels provided withoppositely turned blades carried upon the shaft and adapted to travelalong the shaft contiguously one with the other and revolving inopposite directions.

ln testimony whereoi'rl aiifix my signature in the presence of twowitnesses.

JESSE M. it/VEN V.- R. SANDERS,

J. C. Lnnnnrrnn.

